Centrifugal governor valve assembly for an internal combustion engine



P 1965 G w. NICOLETTI, JR 3,204,651

CENTRIFUGAL GOVERNOR VALVE ASSEMBLY FOR A INTERNAL COMBUSTION ENGINE Filed Sept. 25. 1961 5 Sheets-Sheet 1 /u4 3e 9s -a L 86 H2 4 C 2 z T a Z Z 4 I06 84 2 I50 I36 2 I24 as I28 |34 k g 92 140 I53 6 I60 L1. m

INVENTOR. F' G. I. GEORGE W.N|COLETT| JR.

94% iTQRNEYS Sept. 7, 1965 G. W. NICOLETTI, JR CENTRIFUGAL GOVERNOR VALVE ASSEMBLY FOR AN INTERNAL COMBUSTION ENGINE 5 Sheets-Sheet 2 Filed Sept. 25. 1961 INV EN TOR.

GEORGE W. NIGOLETTI JR.

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A ORNEYS Sept. 7, 1965 G w. NICOLETTI, JR

GENTRIFUGAL GOVERNOR VALVE ASSEMBLY FOR A INTERNAL COMBUSTION ENGINE Filed Sept. 25, 1961 5 Sheets-Sheet 3 FIG.8.

266 208 K 260 264 27s S 258 1 248 2 4--" -256 i 222 250"- AV R\ 278 i i g INV EN TOR.

GEORGE W. NICOLETTI JR.

TORNEYS United States Patent C) CENTRIFUGAL GOVERNOR VALVE ASSEMBLY FOR AN INTERNAL COMBUSTIUN ENGINE George W. Nicoletti, In, Ferndale, Mich, assignor to Holley Carburetor Company, Warren, Micin, a corporation of Michigan Filed Sept. 25, 1961, Ser. No. 140,339 4 Claims. '(Cl. 137-54) The present invention relates to a governing system for an internal combustion engine, and more particularly, to a system having a vacuum .type governor provided with a centrifugal governor control valve including safety mechanism operable to limit speed in the event of failure of drive means connected to the centrifugal governor valve.

Vacuum type engine governors such as shown in United Staes Letters Patent 2,867,196 to Francis, include a vacuum actuated device connected to an engine throttle. The device is connected to a source of vacuum usually resulting from engine operation, such as manifold vacuum, venturi vacuum, or a combination of the two, and control of the device is by an atmospheric bleed connection which when open prevents operation of the device by the applied vacuum. The bleed connection includes a bleed valve which is closed under predetermined con ditions, and when closed permits the application of vacuum to the device to operate the device in such a way as to move the engine throttle toward closed position.

In the past, centrifugal valves have been employed as the bleed valves in the bleed connections to the vacuum type governor. Valves of this type have been driven either by some portion of the engine, such as the ignition distributor or a separate similar drive, in which case the governor is used to protect the engine; or by an output shaft adapted to be connected to the engine by transmission means. The output shaft referred to may be the propeller shaft connected to propel the vehicle, in which case a centrifugal valve rotated thereby controls engine speed to limit road speed of the vehicle. In other cases the output shaft referred to may be the output shaft of a power take-off device, in which case the centrifugal valve connected thereto operates to protect the equipment driven by the power take-off.

Where the centrifugal valve is responsive directly to engine speed for the purpose of protecting the engine, the valve is usually either formed integral with the distributor or mounted directly on the engine so that there is little chance of failure of the drive means for the valve. However, when the centrifugal valve is provided for the purpose of limiting vehicle speed or the speed of auxiliary equipment driven by the power takeoff, the centrifu gal governor valve is usually driven by a cable, and if the cable should break the governor control valve is no longer operable to limit engine speed.

In accordance with the present invention, a pair of centrifugal governor control valves are provided, one of which is responsive directly to engine speed and the other of which is responsive to the speed of an output shaft, as above described, and hence is effective to limit road speed of the vehicle or the speed of operation of equipment driven by a power take-off.

In the past where two centrifugal governor valves have been employed responsive respectively to engine speed and the speed of an output shaft, these valves have been connected in series as disclosed in Wetterhahn 2,921,641, or in parallel. Where the valves have been connected in parallel as contemplated herein, a selector valve is employed to select which of the two valves is in control of the governor. In most cases the maximum permissible vehicle speed or auxiliary equipment speed is such that the engine speed required to produce these maxiice mum speeds is substantially lower than. the maximum speed at which the engine can safely be operated. Accordingly, the valve responsive to vehicle speed or the speed of the auxiliary equipment is set for a value which is attained at a lower engine speed than the speed setting of the governor valve which controls the maximum speed of the engine. This being so, it is apparent that when a drive cable breaks, the governor valve responsive to engine speed or the speed of the auxiliary equipment is no longer operative. If governor valves connected in series are employed the engine speed may increase to a value resulting in excessive road speed or speed of the auxiliary equipment. If the governor valves are connected in parallel and selectively controlled by a selector switch, all governing is lost and the engine speed may increase to a value which is dangerous or harmful to the engine.

Accordingly, it is an object of the present invention to provide a novel centrifugal governor control valve having means associated therewith for preventing loss of governing upon failure in the cable or other drive means connected to the centrifugal governor valve.

More specifically, it is an object of the present invention to provide a centrifugal governor valve means which is normally closed but which opens upon initial rotation and which re-closes at a predetermined higher speed.

Still more specifically, it is an object of the present invention to provide a centrifugal governor valve device comprising series connected centrifugal valves one of which is closed when the valve device is stationary but which opens upon initial rotation thereof, and the other of which is normally open but is adapted to close at and above a predetermined higher speed of rotation.

It is a further object of the present invention to provide centrifugal control valve means including a valve port, a first valve element normally overlying said port movable upon rotation of the valve means to open the port, and a separate valve element movable upon attainment of a predetermined higher speed of rotation to close said port.

It is a further object of the present invention to provide an engine governor system comprising a vacuum operated throttle control device, means connecting said device to a source of vacuum, a first centrifugal atmospheric bleed valve, means for rotating said bleed valve at speeds determined by engine speed, a second centrifugal atmospheric bleed valve, means for rotating said second bleed valve at speeds determined by the speed of an output shaft adapted to be connected to the engine, a selector valve for connecting either of said centrifugal valves to said device, said second centrifugal bleed valve including means effective to maintain said valve closed when stationary.

It is a further object of the present invention to provide a system as described in the preceding paragraph in which the centrifugal bleed valve connected to the output shaft includes a pair of movable valve elements, one of which is normally closed and which remains open while the centrifugal valve is rotating, the other of which is normally open and is adapted to close upon attainment of a predetermined higher speed.

Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawings, illustrating preferred embodiments of the invention, wherein:

FIGURE 1 is a diagrammatic view of an automotive engine having a governor device provided with an engine speed responsive governor valve connected in parallel with a governor valve responsive to the speed of an output shaft.

FIGURE 2 is an enlarged sectional view through a selector valve shown in FIGURE 1.

FIGURE 3 is a view similar to FIGURE 2 showing a somewhat different embodiment of selector valve.

FIGURE 4 is an enlarged vertical cross-section on the line 44, FIGURE 1, looking in the direction of the arrows.

FIGURE 5 is an exploded perspective view, partly in cross-section, of some of the elements shown in FIG- URE 4.

FIGURE 6 is a view similar to FIGURE 4 showing the auxiliary governor in an operating position.

FIGURE 7 is a fragmentary cross-sectional view taken on the line 77, FIGURE 6.

FIGURE 8 is an enlarged vertical cross-sectional view showing another embodiment of the invention.

FIGURE 9 is a fragmentary sectional view of the device shown in FIGURE 8, illustrating the position of parts attained during operation thereof.

With the foregoing general description of the invention in mind, reference is now made to the drawings and particularly to FIGURE 1. In this figure there is diagrammatically illustrated a portion of a truck 10 having the usual engine 12, carburetor 14, and air cleaner 16. A vacuum actuated engine governor is provided and may be of conventional type such for example as shown by Francis 2,867,196 or Wetterhahn 2,921,641. Governors of this type are permanently connected to a source of vacuum, preferably vacuum developed as a result of engine operation. Excellent results are obtained when the source of vacuum combines manifold vacuum and venturi vacuum since the resultant vacuum may be sub stantially uniform. Operation of the governor 20 is controlled by one or more atmospheric bleed valves, as will subsequently be described. When air under atmospheric pressure is bled to the governor 20 the vacuum applied thereto is rendered ineffective to produce actuation thereof. However, when the flow of atmospheric air is cut off or reduced, the vacuum applied to the governor moves the governor throttle toward closed position.

The engine 12 includes a distributor 22 and a centrifugal governor bleed valve 24 associated therewith. The centrifugal bleed valve 24 includes a centrifugal device rotatable with the rotating part of the distributor 22 and accordingly, the valve 24 is responsive directly to engine speed.

The engine 12 is adapted to be connected to the engine propeller shaft 26 through a standard transmission 28 and in this instance is provided with a power take-oil. unit 30 including a power take-01f shaft 32 selectively coupled to the engine under the control of a lever 34. A second centrifugal bleed valve 36 is provided which is coupled to the power take-off 30 by a flexible drive cable 38.

A solenoid actuated selector valve 40 is provided for connecting either one of the bleed valves 24 or 36 to the governor 20, the selector valve 40 being controlled by a switch 42 conveniently located in the cab of the vehicle. When the valve 24 is in control air under atmospheric pressure is supplied from the air cleaner 16 through a passage 44 to the bleed valve 24, and when this valve is opened, through passages 46 and 48. When the selector valve 40 is actuated to place control of the engine under the bleed valve 36 atmospheric air is supplied through passage 50, bleed valve 36, and passages 52 and 48 to the governor 20.

Referring now to FIGURE 2 there is shown an enlarged sectional view through the selector valve 40. The valve 40 includes a cylindrical chamber 56 in which a valve element 58 is rotatable. The valve element 58 includes a recess 60 at one side thereof, which when the valve element is in the illustrated position, affords communication between passages 46 and 48. The rotatable valve element 58 is connected by suitable means such as a link 62, to the plunger of a solenoid indicated generally at 64, When energized the solenoid maintains the valve in one of its two limiting positions and suitable spring means (not shown) returns the valve to the opposite position when the solenoid is deenergized. Alternatively of course, the solenoid may be connected to shift the valve element 58 to either of its operating positions so that the valve element will remain in selected position without requiring continued energization of the solenoid. The valve element 58 includes a passage 66 which when the valve element is rotated counterclockwise from the position shown in FIGURE 2, will be effective to provide communication between the passages 48 and 52.

Referring now to FIGURE 3 there is illustrated a second embodiment of the selector valve. In this case the valve body 68 is provided with an internal passage 70 communicating with passages 72 and 74. A valve element 76 is shiftable by solenoid means indicated generally at 78, between the full line position illustrated in FIG- URE 3, at which it interrupts communication between passages '70 and 72, and the dotted line position in which it interrupts communication between the passages 70 and 74.

Referring now to FIGURES 4-7, details of the centrifugal bleed vave 36 are illustrated. The valve 36 comprises a housing including a main body 80 having a depending tubular portion 82, and a cover 84 including an upward generally cylindrical extension 86. The cover is connected to the main body 80 by suitable fastening means such as the screws indicated at 88. The governor valve shaft includes an enlarged intermediate portion 92 located within the valve housing and provided with a transversely extending cylindrical opening 94. The upper end portion 96 of the shaft 90 is provided with an axial passage 98 communicating with the transverse passage 94 therethrough. The previously described passage 52 extending between the valve 36 and the selector valve 40 is connected to the extension 86 of the cover 847 Thrust Washers 100 and 162 are fitted as by a press fit, within recesses provided in the body 80 and cover 84 respectively, and bear against shoulders 1136 provided at opposite ends of the enlarged intermediate portion 92 of the shaft 90. The shaft 90 is further journaled within a bearing 108 press fittted in the bore 110 of the depending tubular portion 82 and in a bearing 112 press fittted within the bore 114 of the upward extension 86 of the cover 84. A seal 116 of suitable material, such for example as rubber, is provided to seal the shaft 90 from the bore 110 and the chamber 118 formed within the body 80.

A rotor assembly indicated in its entirety at 120 comprises a tubular body 122 press fitted into the transverse opening 94 of the shaft 90. The body 122 is provided with a shoulder 124 engageable against an end of the enlargement 92 of the shaft to locate the body 122 in a predetermined position. In this position the interior of the tubular body 122 communicates with the passage 98 extending through the upper end of the shaft 90 through a port 126.

The rotary tubular body 122 is closed at one end with an adjusting plug 128 provided with threads as indicated at 130. Adjustment of the plug is accomplished by a screw driver, the outer end of the plug 128 being slotted as indicated at 132. The inner end of the plug is provided with a transversely extending slot 134 across which extends a pin 136 to which one end of a calibrated tension spring 138 is connected. The other end of the spring 138 is connected to a centrifugal valve element 140 by a pin 142 extending across slot 144 provided in the valve element. A stop pin 146 is provided in the tubular body 122 limiting movement of the valve element 140 to the left as seen in FIGURE 4.

The valve element 40 is of polygonal shape and is loosely slidable longitudinally in the tubular body 122.

Due to its polygonal shape, free passage of air is af forded between the interior of the tubular body 122-at the right of the valve element 140 and the passages 98 and 52.

Valve element 140 is associated with a cup-shaped body 150 press fitted within the end of the tubular body 122 opposite the plug 128. Radially extending passages 152 are provided extending through the wall of the tubular body 122 and registering with openings 153 in the side wall of the cup-shaped body 150. The end wall of the cup-shaped body 150 is provided with a valve opening 154 adapted to be closed by the nose portion 156 of valve element 140 when it moves to the right as seen in FIGURE 4, under the influence of centrifugal forces and at a speed determined by the effectiveness of the spring 138.

The construction and operation of the governor control valve assembly 36 as thus far described, is essentially the same as those commonly employed prior to the present invention. As the speed of rotation of the shaft 90 increases the rotor assembly 120 is rotated at higher speed and the valve element 140 moves radially outwardly toward the valve seat 154. When the speed of rotation of the shaft 90, which in this instance is determined by the speed of rotation of the output shaft 32 of the power take-off device, reaches a predetermined value as determined by the setting of the adjusting plug 128, the nose 156 of the valve element 140 closes the valve port 154, terminating the flow of air through passages 34 and 52 to the vacuum operated governor 20. At this time the engine throttle is moved toward closed position to limit engine speed to a value which will result in driving the output shaft 32 at a speed within the predetermined safe limits.

In accordance with the present invention means are provided which are effected to close the engine throttle in the event of failure of the flexible drive shaft 38. This means is associated with the cup-shaped body 150 as best seen in FIGURES 4 and 5. The body 150 is internally threaded and receives a threaded tubular body 160. The inner end of the body 160 is reduced as indicated at 162 in FIGURE 5, and is transversely slotted to leave circumferentially spaced abutment elements 164 leaving passages 165 affording communication between passages 152 and the valve port 154. The outer end of the body 160 is provided with a guide opening 166 which receives the guide stem 168 of a poppet valve 170, the head of which is provided with a rubber gasket 172 adapted to close the valve port 154 by engagement with the inner end of the cup-shaped body 150. The poppet valve 170 is normally rettained in closed position by a very light compression spring 174. The arrangement is such that when the centrifugal valve assembly 120 is not rotating the poppet valve 170 is closed and prevents air bleed to the engine governor. However, upon initial rotation of the rotatable valve assembly 120 the poppet valve 170 opens and remains open so long as the valve assembly is in rotation. At some higher predetermined speed of rotation the main bleed valve 140 closes in the usual way.

The result is that the valve assembly 128 is arranged to fail safe. If the drive cable 38 breaks the valve assembly 120 ceases to rotate and the relatively light compression spring 174 is effective to move the poppet valve 170 to the closed position illustrated in FIGURE 4.

FIGURE 6 is generally similar to FIGURE 4 except that the parts are illustrated in the position which they assume while the engine is driving the power take-off shaft at a speed within the permissible speed range. In this figure it will be observed that centrifugal force has moved the poppet valve 170 to the right from the position illustrated in FIGURE 4, so that flow of atmospheric air is permitted from the passage 50 through passages 153, 152 and 165, through the valve port 154, past the valve member 140, through the passage 98, to the passage or conduit 52 leading to the selector valve 40.

Referring now to FIGURES 8 and 9 there is illustrated a somewhat different embodiment of the invention. In

these figures the centrifugal bleed valve is indicated generally at 200 and comprises a housing including a main portion 22 formed to provide an interior chamber 204 and having a downwardly extending generally tubular portion 206. The main portion 202 of the housing is completed by a cover member 208 having an upwardly extending tubular portion 210. A shaft 212 is provided having an enlarged intermediate portion 214 located Within the chamber 204 and retained therein by thrust washers 216 and 218. The shaft is connected toa flexible drive shaft 220 which may be connected for rotation in timed relation to the output shaft of a power take-off or the like, but which in this instance is intended to be connected to the transmission of the vehicle so as to be driven at speeds bearing a predetermined relationship to road speed of the vehicle.

A centrifugal bleed valve assembly indicated generally at 222 is provided and is adapted to control the flow of bleed air through the assembly. For this purpose the main housing 202 is provided with a boss 224 having passages 226 and 228 therein. The passage 226 affords communication between an external conduit 230 and the air cleaner such as illustrated at 16 in FIGURE 1. The passage 228 connects to the throttle controlling governor 20 as previously described.

The shaft 212 is provided with an elongated axially extending passage 232 which at its lower ends connects with a cross passage 234 communicating through ports 236 provided in a bearing 238 with the passage 228. It will of course be appreciated that the passage 232 may be drilled from one end of the shaft 212 and] one end thereof closed by a suitable plug (not shown).

The shaft 212 at its intermediate enlarged portion 214 is provided with a transverse opening 240 which receives the tubular portion of the rotatable centrifugal bleed valve assembly 222. This bleed valve assembly comprises an elongated body 241 having a longitudinally extending passage 242 therein terminating short of one end thereof, as indicated at 244, and closed at its other end by a plug 248. The left hand end of the body 241, as seen in FIG- URE 8, is enlarged, forming locating shoulders 250 engageable against the sides of the intermediate enlarged portion 214 of the shaft 212 and is retained in the transverse opening 240 by a press fit relationship. The body 241 is provided with a port 252 in registration with the axially extending passage 232 in the shaft 212. The body 241 is provided with a plurality of radially extending ports 254 and at the adjacent end, the body is threaded and carries a nut 256 supporting a spring seat 258.

Slidable on the laterally extending portion of the body 241 which is provided with the valve ports 254, are a pair of independently movable valve elements 260 and 262. A relatively light compression spring 264 extends between the valve seat 258 and the valve element 260. A relatively stronger compression spring 266 extends be tween the spring seat 258 and the valve element 262. It will of course be apparent that the effectiveness of the springs, and particularly the spring 256, may be varied by adjusting the position of the nut 256.

The parts are shown in FIGURE 8 in the normal or inoperative position and at this time it will be observed that the main speed responsive valve 262 is positioned radially inwardly of the ports 254, but that the safety valve element 260 is at this time urged radially inwardly by the spring 264 into abutment with the valve 262, in which poistion it overlies the valve ports 254.

When the centrifugal valve assembly 222 is in rotation, the centrifugal force is sufficient to shift the valve 260 radially outwardly to the position shown in FIGURE 9. However, at low speed relatively heavier compression spring 266 is sufficient to hold the valve element 242 to the left or radially inwardly of the ports 254. According ly, in this assumed position which is attained while the controlled speed is within the acceptable range, there is a flow of bleed air through the passage 230 into the cham- 7' her 2M, thence through the valve ports 254 into the interior chamber 242 of the body 242i, thence through the port 252, passages 232, 234, port 236, and passage 223 to the external passage or conduit 27th leading to the vacuum actuated governor.

When the speed of the shaft 212 reaches the predeteo minded upper limit of its acceptable speed range, the valve 262 moves outwardly to the position shown in FIGURE 9 where it overlies the ports 25d and hence, terminates how of bleed air to the vacuum governor, with the result that the engine throttle is moved toward closed position.

it will of course be apparent that if the flexible drive shaft 22% should brea r, the centrifugal valve assembly 222 will cease to rotate and the springs 264 and 266 will shift the valve elements and respectively to the position shown in FIGURE 8, thus terminating flow of bleed air and resulting in movement of the throttle valve toward closed position as above described. This of course will serve as a signal to the operator that the governor is not operating.

In the embodiment of the invention illustrated in FIG- URE 8 it will be observed that the upper end of the shaft 212 is provided with a drive connection such as the slots 272 for connection to a tachometer or speedometer drive. The upper end of the cover 268 is threaded as indicated at 274'to provide means for securing the tachometer or speedometer drive connection in place.

it will further be observed that in this embodiment of the invention the main housing body 294 is provided with a relatively large threaded opening adapted to receive a closure plug 27% which when removed affords access to the spring adjusting nut 256 when rotated into registration with the opening 276.

Summary and operation in summary, the invention of this disclosure is an iniprovement over prior governor control valve structures, specifically for the purpose of providing governing in the event that a cable or other drive to the centrifugal governor control valve should break. This is accomplished by providing the rotatable portion of the control valve assembly with valve means normally closed when not rotating, open when rotatec at speeds below a predetermined governed speed, and closed at and above predetermined governed speed. Specifically, this is accomplished by providing a pair of independently movable valve elements one of. which is effective to close a bleed valve port when the centrifugal bleed valve is not rotatable, but which is movable to uncover the port when the bleed. valve is rotated, the other of which is movable t close the port only at and above a predetermined speed of rotation of the centrifugal valve.

The drawings and the foregoing specification constitute a description of the im roved governing system for an internal combustion engine in such full, clear, concise and exact terms as to enable any person skilled in the art to practice th invention, the scope of which is indicated by the appended claims.

What I claim as my invention is:

it. A centrifugal governor valve assembly comprising a shaft, a valve carried by and rotatable with said shaft, said valve ll1ClUdlT a valve port, a first valve element movable radially cl said shaft and located radially outwardly of said'valve port, resilient means engaging said valve effective to retain said valve in closed position only when said valve assembly is not in rotation, a second valve clement carried by and rotatable with said shaft and located radially inwardly of said valve port, resilient means opposing outward movement of said second valve element into valve closing position and effective to permit closure of said second valve element only upon attainment of a predetermined speed.

2. A centrifugal governor valve assembly comprising a shaft, a tubular device extending transversely of said shift, said tubular device having a valve port, a pair of independently movable valve elements supported by said tubular device for movement with respect thereto, resil'ent means controlling radial movement of said valve elements as a result of centrifugal force, one of said valve elements being effective to close said port when said tubular device is not in rotation and to open said port whenever said tubular device is in rotation, the other of said valve elements being effective to move into position to close said port only at and above a predetermined speed of shaft rotation.

A centrifugal governor valve assembly as defined in claim in which said valve port is formed in a partition extending transversely of said tubular device, in which said. first mentioned valve element is located radially outwardly of said partition, and in which said second mentioned valve element is located radially inwardly of said partition.

A centrifugal governor valve assembly as defined in claim 2 in which said valve port is provided to extend transversely through said tubular device, and in which said valve elements are mounted for slidable movement on said tubular device.

lSAD-GR WElL, Prim ry Examiner.

RICHARD B. WIL (ENSON, CLARENCE R. GOR- DON, Examiners. 

1. A CENTIFUGAL GOVERNOR VALVE ASSEMBLY COMPRISING A SHAFT, A VALVE CARRIED BY AND ROTATABLE WITH SAID SHAFT, SAID VALVE INCLUDING A VALVE PORT, A FIRST VALVE ELEMENT MOVABLE RADIALLY OF SAID SHAFT AND LOCATED RADIALLY OUTWARDLY OF SAID VALVE PORT, RESILIENT MEANS ENGAGING SAID VALVE EFFECTIVE TO RETAIN SAID VALVE IN CLOSED POSITION ONLY WHEN SAID VALVE ASSEMBLY IS NOT ROTATION, A SECOND VALVE ELEMENT CARRIED BY AND ROTATABLE WITH SAID SHAFT AND LOCATED RADIALLY INWARDLY OF SAID VALVE PORT, RESILIENT MEANS OPPOSING OUTWARD MOVEMENT OF SAID SECOND VALVE 